The term “wave energy” is used herein to include radiation as well as wave energies transmitted by various mediums, and embraces electromagnetic waves or radiations; sonic, supersonic, and ultrasonic waves; neutrons, protons, deuteron, and other corpuscular radiations. The term “electromagnetic waves” includes, e.g., X-ray, gamma-ray, ultraviolet, infra red, and visible light rays, and short electric and radio waves. These definitions and terms are consistent with those used by the U.S. Patent and Trademark Office for classification purposes.
Electromagnetic radiation (EMR) is one of the most pervasive forms of wave energy known and used by man. Sunlight, both within and beyond the visible spectrum, is one example of EMR wave energy that has been highly beneficial to man, and all life on earth. Man has harnessed the benefits of EMR through the development of such great inventions such as the light bulb, X-rays and radio waves. Another utilization of wave energy, welding, has been an important factor in the development of modem technologies. Similarly, the steel industry grew rapidly due to another wave energy technology known as the electric arc, used for melting iron ore and converting it to steel.
Although the industrial revolution has brought about the luxuries and simplicities of life, there has been a world-wide downside - pollution. Nowadays, it is common to find many waterways, drinking water sources, air and soils contaminated with pollutants. Although many technologies have been developed for removing contaminants from water and air, more and more engineers and scientists are turning to ultraviolet (UV) light systems for treating fluids.
One of the greatest inventions of all time is the light bulb. One of the earliest forms, Thomas Edison's carbon arc light bulb, has all but faded into extinction. A few very large carbon arc systems such as World War II vintage carbon arc searchlights are available today as rebuilt units. However, in general carbon arc lights are not utilized today for industrial and residential lighting, as searchlights or for photochemical reaction type applications. The carbon arc light bulb has been almost entirely replaced for those purposes by fluorescent bulbs, high pressure mercury vapor lamps, compact ceramic lamps and high pressure xenon lamps.
Another form of wave energy is sonic energy, and particularly ultrasonic energy. Ultrasonic waves are more commonly referred to as ultrasound. Ultrasound plays an important role in medical diagnostics, submarine sonar, ship sonar, non-destructive testing of metal, and cleaning equipment.
Photochemical reactions are well known and well documented. The use of electromagnetic radiation (EMR) particularly within the ultraviolet (UV) region, between 4 to 400 nanometers (nm), for treatment of fluids such as disinfection of drinking water and wastewater, free radical generation (hydroxyl radicals, chlorine radicals, etc.) and removal of noxious air contaminants such as VOCs, NOx, SOx from flue gas (off gas, tail gas) has gained in popularity over the past decade. In addition, advanced UV processes such as Advanced Oxidation, which incorporates UV light with an oxidant such as ozone or hydrogen peroxide, generate free radicals for decomposition of contaminants. Another UV art, which is rapidly receiving attention, is PhotoCatalytic Oxidation (PCO). PCO technology incorporates a semi-conductor catalyst in combination with UV radiation for generation of free radicals. PCO technology can use sunlight since the photons of interest for the most common photocatalyst, TiO2, lies between 320 to 400 nm and more specifically at about 365 nm.
Although there are many methods and devices known in the art, their applications are specific and limited. It is highly unlikely, for example, that an EMR device used for water disinfection can be used for air purification. Likewise, a PCO device designed for air disinfection has significant drawbacks when an attempt is made to utilize that technology in a liquid environment. This can be clearly demonstrated by a close review of the prior art.
There are a number of major obstacles which have not been overcome by the prior art. One major obstacle is residence time versus absorbance. The result of the failure of the prior art to overcome this obstacle is perceived by the end-user (customer) as a problem of “not having enough lights,” of “light penetration,” and/or of “excessive energy requirements (inefficient)”. When a photochemical reactor is designed and built for a specific set of parameters, the actual parameters in which the reactor is operated are variable and often change after the reactor put into service. Operators must make do with the photochemical reactor or the reactor is taken out of operation and decommissioned.
Given the past inadequacies of wave energy systems, in particular EMR systems employing UV/visible radiation, many designs have incorporated more lights, transparent glass sleeve wipers, redundant systems, or methods, which allows for more/better contact between the contaminants and the photons or the photocatalyst and the photons. However, the changes still do not overcome the problem of residence time versus absorbance. Thus, if the problems associated with both residence time and absorbance can be eliminated or solved, then an ideal photochemical reactor as well as method (for photochemical reactions) can be designed for many different applications. The problem of absorbance is inversely proportional to EMR transmission.
A number of attempts to advance the technology and to overcome problems and drawbacks in this field have been made, and are reflected in a number of patent documents.
U.S. Pat. No. 3,998,477—dated Dec. 21, 1976, discloses a device for non-rigid connection of two rigid cylindrical pipes, which comprise the combined use of flexible double lipped gaskets and toroid flexible gaskets surrounding a bulb-shaped zone formed in one of the pipes. The device is particularly useful for fastening fragile tubes containing light emitters to metal reactors used for photochemical processes.
U.S. Pat. No. 4,002,918—dated Jan. 11, 1977, discloses an apparatus for the irradiation of fluids in which the fluid is conducted along the walls of a container having walls which are permeable for the radiation to which the fluid is exposed. Radiation sources are arranged around the container and an active rotor is disposed within the container. The rotor consists of a body having axial bores and pins movably disposed in the bores and adapted to engage with their front ends the container walls thereby to wipe any deposits from the container walls during rotation of the rotor.
U.S. Pat. No. 4,317,041—dated Feb. 23, 1982, discloses various embodiments of photo-reactors in which there are at least two radiation chambers with a window arranged therebetween. UV radiation is introduced into one of the chambers at a side opposite the window so that it passes through that chamber, through the window and into the other chamber. The fluid medium to be purified is passed through the chambers and subjected to the radiation while in the chambers. The flow of the medium is through the chambers in series in some embodiments and in parallel in others. An embodiment is disclosed wherein a recirculation line is established around the reactor with the recirculation being continuous or intermittent. When intermittent the purified fluid medium also is drawn off intermittently, between the periods of recirculation. In some embodiments, the amount of radiation traversing all the chambers is monitored. If the monitored amount drops below a given amount, the apparatus is shut down. Alternatively, the rate of flow of the medium is adjusted, based on that monitored amount, with the rate of flow increasing or decreasing, respectively, in response to increases or decreases in that amount.
U.S. Pat. No. 4,476,105—dated Oct. 9, 1984, relates to a process for producing gaseous hydrogen and oxygen from water. The process is conducted in a photolytic reactor which contains a water-suspension of a photoactive material containing a hydrogen-liberating catalyst. The reactor also includes a column for receiving gaseous hydrogen and oxygen evolved from the liquid phase. To avoid oxygen-inactivation of the catalyst, the reactor is evacuated continuously by an external pump which circulates the evolved gases through means for selectively recovering hydrogen therefrom. The pump also cools the reactor by evaporating water from the liquid phase. Preferably, product recovery is effected by selectively diffusing the hydrogen through a heated semipermeable membrane, while maintaining across the membrane a magnetic field gradient which biases the oxygen away from the heated membrane. This promotes separation, minimizes the back-reaction of hydrogen and oxygen, and protects the membrane.
U.S. Pat. No. 5,126,111—dated Jun. 30, 1992, discloses a method of removing, reducing or detoxifying organic pollutants from a fluid, water or air, by contacting the fluid with a photoreactive metal semiconductor material in the presence of ultraviolet light of a wavelength to activate the photoreactive material. This is improved by simultaneously contacting the photoreactive material with a substance that accepts electrons and thus inhibits hole-electron recombination. Such substance will be such as to readily accept electrons either from the conduction band or from superoxide ions, and to rapidly dissociate into harmless products.
Still other photoreactors are described in U.S. Pat. Nos. 3,567,921; 3,769,517; 3,924,246; 4,296,066; 4,381,978; 4,454,835; 4,488,935; 4,544,470; 4,774,026; 4,863,608; 4,868,127; 4,957,773; 5,045,288; 5,094,815; and 5,149,377.
U.S. Pat. No. 5,439,652 (Sczechowski, et al.) issued on Aug. 8, 1995 states that a Beer's law type expression was found for the transmitted light as a function of the TiO2 loading. From this relationship, the calculated light penetration depth for the 0.4% (by weight) Degussa TiO2 slurry used in these experiments was approximately 1 mm.
U.S. Pat. No. 5,994,705 (Cooke, et al) issued on Nov. 30, 1999 is a continuation of U.S. application Ser. No. 08/946,647, filed on Oct. 7, 1997 now U.S. Pat. No. 5,866,910 which is a continuation of U.S. application Ser. No. 08/438,234, filed on May 9, 1995, now U.S. Pat. No. 5,696,380 discloses a flow-through photochemical reactor includes a reactor body, which circumscribes a longitudinally extending channel having a generally annular cross section. This channel accommodates fluids passing between an inner wall of the reactor body and an outer wall of a photon-transmitting tube that is housed internally thereof. In addition, the reactor includes mechanically static, fluid-dynamic elements for passively inducing substantial turbulent flow within a fluid as it passes through the channel. This arrangement substantially increases the uniformity of the fluid's exposure to photons radiating from a source within the tube into the fluid and it is conducted through the channel.
Calgon Corporation's U.S. Pat. No. 6,565,803 issued to Bolton, et al. on May 20, 2003 and titled, “Method for the inactivation of cryptosporidium parvum using ultraviolet light,” has a major drawback. The system utilizes mercury vapor bulbs housed in a quartz tube. Mercury is a pollutant that is transferred via the food chain. Any UV system incorporating a “bulb” is prone to burn out. Further, the glass or quartz envelope and the bulb become solarized due to the UV light. Consequently, dosages as specified within the '803 patent may not be sufficient to inactivate cryptosporidium.
Many other types of wave energy apparatuses are known in the prior art, but none of the known prior art utilizes the approaches encompassed within the scope of the present invention.